Link the vpp application against libvnet.so, not libvnet.a

Turn of srp, mainly as an example of how to restructure a featurette
for selective disablement.

Change-Id: Id3364c58a8711b103939f4434adfa67177380f67
Signed-off-by: Dave Barach <dave@barachs.net>
diff --git a/vlib/vlib/unix/main.c b/vlib/vlib/unix/main.c
index 6ff63f8..d6976b1 100644
--- a/vlib/vlib/unix/main.c
+++ b/vlib/vlib/unix/main.c
@@ -431,7 +431,8 @@
     return i;
   
   unformat_init_command_line (&input, (char **)vm->argv);
-  vm->init_functions_called = hash_create (0, /* value bytes */ 0);
+  if (vm->init_functions_called == 0)
+      vm->init_functions_called = hash_create (0, /* value bytes */ 0);
   e = vlib_call_all_config_functions (vm, &input, 1 /* early */);
   if (e != 0)
     {